OAKLAND -- BART trains will continue to run -- for now -- after Gov. Jerry Brown told unions late Sunday to go back to work for at least the next seven days, avoiding another crippling rail strike.

With negotiations down to the wire, BART and its unions announced that Brown had requested a week-long delay to the shutdown that was set to begin Monday morning. It came just two hours before both sides were set to hit an 11:59 p.m. deadline to reach a deal.

BART Board President Tom Radulovich wrote Brown requesting a 60-day cooling off period, a strategy used by previous administrations to delay strikes over the last few decades -- most recently, in 2001.

The delay also includes a state investigation into the labor talks, headed by a three-person panel appointed by the governor, and their conclusion by next Sunday will impact whether Brown extends the contract another two months, Brown's office said. The governor said "the strike will significantly disrupt public transportation services and will endanger the public's health, safety, and welfare."

"The board is directed to provide me with a written report within the next seven days," Brown said in a letter to union and management leaders. "For the sake of the people of the Bay Area, I urge -- in the strongest terms possible -- the parties to meet quickly and as long as necessary to get this dispute resolved."

Unions were not pleased, but they hoped the state investigation would help them broker a better deal.

"We are extremely disappointed that this even has to happen," Antonette Bryant, president of the local Amalgamated Transit Union, said.

Pete Castelli, executive director of the local Service Employees International Union, added: "We want a contract. How long does this have to go on?"

But BART leaders, who previously had rejected the notion of a two-month cooling off because October is a busier time for riders, changed their mind to avoid the imminent shutdown. Radulovich said management asked unions for a seven-day extension, but they declined, so they turned to Brown around 5 p.m. as it became clear they were not close to reaching a settlement.

"It ended up being our only option to keep the trains running," Radulovich said late Sunday, adding that Brown instructed them to keep negotiating during the coming week. "We had the potential of a strike in October versus the reality of a strike tomorrow and we just didn't want to see this shut down again."

Appointed under an obscure state law that covers public transportation disputes, the chair of the board investigating the BART labor talks is Jacob Applesmith, a senior advisor to Brown and director of the Department of Alcoholic Beverage Control. Also on the panel will be San Francisco Human Resources Director Micki Callahan and the former president of the State Building and Construction Trades Council of California, Robert Balgenorth.

It comes after Brown in July appointed two top state mediators to oversee the talks. They then brokered a 30-day deal to stop the first, 4½-day BART shutdown on July 5, which set up Sunday night's deadline.

Without an agreement, the 200,000 people who ride BART roundtrip each day would have been left looking for another way to get around, while many commuters would see gridlocked freeways and standing-room only buses.

The deal came as both sides had spent the last four months negotiating without significant progress on the key issues that had divided them: increases to pay and pension and health care contributions. Going into the weekend, BART said it was still far apart on all three items, and earlier Sunday evening, union leaders reported no significant progress.

Minutes later, Chris Finn, recording secretary for the local Amalgamated Transit Union, said no progress had been made but that union leaders were ready to negotiate all night: "We've got a hotel room and we're ready to meet around the clock if need be," he said.

As the day began, Josie Mooney, lead negotiator for the local Service Employees International Union, walked into negotiations and said: "We have a long way to go but at least the parties are making some exchanges."

After a 14-hour bargaining session on Saturday that ended around 11:30 p.m., the talks resumed on Sunday at 10 a.m. and ended with the announcement of a seven-day delay at 10 p.m.

As the talks dragged on, frustrated commuters had to decide whether to stay up late awaiting word on a strike or go to bed early so they could wake up to beat rush hour.

Jacob Acosta, 26, of Oakland was planning to take the ferry Monday, just like he did during last month's BART strike.

"It'll add about 45 minutes to my commute, but it's a pleasant ride," said Acosta, who lives about a mile from the terminal. "I know people further out in the East Bay, like in Concord and Walnut Creek, have it a lot worse."

Traffic officials with the 511 hotline and Website said the number of overall travelers on Bay Area roads, trains, buses and ferries would have increased 10 percent compared to the last strike, which happened during the light Fourth of July week. Even then, freeways that parallel the BART route -- namely the Bay Bridge, Highway 24 and Interstate 580 -- were gridlocked while seats on buses and ferries were hard to find.

BART union workers have complained that their pay has remained flat in the past four years, since their last contract was signed, and they deserve a raise because BART is enjoying record revenue.

But management counters that BART workers are already among the best-compensated transit workers in the country. Currently, the 2,300 blue-collar union workers at BART make an average of $76,500 in gross pay, do not contribute toward their pension and pay $92 for medical insurance each month.

The latest available offers had BART proposing a four-year deal with 8 percent pay increases and a few percentage point bumps to health and pension contributions. Unions, meanwhile, had offered a three-year deal including more than 20 percent wage increases and small bumps to benefits contributions.

"We're ready to talk, as soon as (Monday) morning, if the other side is ready to go," Radulovich said.